Cellulosic material and method for preparing same



Patented Au 8, 1939" MATERIALIAND METHOD FOR PREPARING SAME' I .ocLLULosro PATENTVVOFFICE Winfield Walter Heckert, Ardentown, Del., as-

signor, by mesne assignments, to E. I. du Pont q de Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application June 17, 1936, Serial No. 85,815. In Germany June 18, 1935 16 Claims.

' This invention relates to the manufacture of cellulosic materials such as cords, threads, yarns, filaments, fibers and the like or fabrics made therefrom and films, pellicles, caps, bands and the like-which have improved affinity for acid or direct dyestuffs.

Direct dyes possess the property of dyeing cotton, linen and regenerated cellulose as well as wool and silk and form a very important class of coloring matter. Direct dyes in general are dischargeable, which is an important characteristic and is necessary for the manufacture of an important class of textile fabrics known as print goods. Acid dyes are used almostexclusively for dyeing wool, silk and other animal fibers and are also extremely valuable. I

Regenerated cellulose structures are readily dyed with direct colors. Regenerated cellulose, however, has practically no aflinity for acid dyestuffs and when regenerated cellulose fibers are mixed with wool to produce composite threads or yarns or when regenerated cellulose yarns are fabricated with woolen yarns to produce a mixed fabric, the product cannot be dyed to a uniform color with acid dyestuffs. Although the mixed fabric. might be fairly uniformly dyed with a direct dye, it is at times desirable and preferable to use acid dyestuffs because of differences'in light fastness, laundry fastness, etc., between direct dyes and acid dyestuffs.

Cellulose derivative structures and especially the cellulose esters, such as cellulose acetate, can

only be dyed with expensive dyestuffs and by,

means of special, expensive and diflicult pro- 5 cedures. For the most part, none of the cellulose acetate dyes are satisfactorily dischargeable and consequently cellulose acetate fabrics cannot be subjected to discharge printing as are fabrics of wool, cotton, regenerated cellulose rayon, or 40 the like. Furthermore, cellulose acetate has no afiinity for either the acid or direct dyes. It is because of this that cellulose acetate has been used to a considerable extent where cross dyeing effects are desired, but on-the other hand, when cellulose acetate is mixed with regenerated cellulose, cotton, wool or natural silk, and uniform, solid color is desired, it has been necessary to go through a long, expensive procedure attended by undesirable changes in the yarn or fabric properties.

It is known that the aflinity of regenerated cellulose yarn for acid dyes may be considerably enhanced by incorporating proteins in the spinning solution. Furthermore, it has been proposed to harden the protein contained in the ring constituents, an aldehyde regenerated cellulose thread'with formaldehyde to render it-resistant to chemicals which, unfortunately, decreases the affinity of the added protein for acid dyestuffs. More recently, it has been proposed'to treat the protein with a material to insolubilize it, for instance to form reaction products, which arenot easily removed from the fibers.

It is therefore an object of this invention to improve the aflinity of cellulosic structures for dyestuffs.

Another object of this invention is to improve the aflinity of cellulosic structures for, direct acid dyestuffs.

Another object of this invention is to improve the amnity of regenerated cellulose structures for acid dyestuffs.

Still-another object of this invention is to improve theafiinity of cellulose esters, such as cellulose acetate, for direct acid dyestuffs.

Other objects will be apaprent from the description that follows.

The objects of this invention are accomplished in. general by incorporating in the cellulosic material in any suitable manner an amine-phenolaldehyde resin prepared by reacting a phenol having at least two free reactive positions, 1. e.,

positions ortho and para to the phenolic hydroxyl, and containing only organic groups as (particularly formaldehyde) and an organic compound, preferably of not over six carbon atoms which has at least one amino nitrogen atom joined to an allphatic carbon atom, i. e., a carbon atom which is not a part of an aromatic ring, and to at least one hydrogen atom, and isolating the resulting resinous reaction product.

n; is preferred that these resins be insoluble in water and soluble in dilute aqueous mineral or organicacids when used in cellulose derivative structures. Some of these resins are soluble in dilute aqueous caustic solutions, in acetone and in certain other solvents as set forth hereinafter. The preparation of certain of these resins is described in United States Patent No. 2,031,557 to Bruson and certain others in United States Letters Patent of Harmon and Meigs, No.

tain of these amino phenol aldehyde resins, the following examples are given:

EXAMPLE A.Phenol-formaldehyde-dimethylamine-ammonia resin A solution of 18 grams (0.4 mol) of dimethylamine in 32.4 grams (0.4 mol) of,37% aqueous 2,098,869. To illustrate the preparation of cerwashing with ice cold water.

weighed 74 grams. It wasa yellow material formaldehyde was added with mechanical stirring-and cooling to 53.5 grams (0.5 mol) of 88% phenol. To the above mixture, a solution of 81 grams (1 moi) of 37% aqueous formaldehyde and 30.4 grams (0.5 mol) of 28% q eous ammonia was added with cooling; The resulting solution was gradually heated in a water bath to 90 C. and held at that temperature for hours. The resulting resin was purified by grinding it to a uniform slurry in the presence-of a little water in an ice cold mortar, followed by filtration and After drying, it

which softened slightly abo e room temperature.

It was soluble in acetone, ethyl acetate, dioxan, aqueous sodium hydroxide, 1.5% aqueous acetic acid, 3% formic acid, and 90% toluene- 10% ethanol mixture.

The crude phenol lignin used in this preparation was made as follows:

A 3-liter 3-neckedflask was equipped with a hook-type mechanical stirrer, wide bore air reflux condenser and thermometer and mounted in an oil bath. The flask was charged with 900 grams of phenol. the stirrer started and 190 grams of a fine grade of spruce wood flour (100 mesh or better) were added through the condenser while the tempm'ature of the phenol was increased from to 116 C. Then 25 grams of concentrated hydrochloric acid were added all at once. After the reaction mixture had become homogeneous (about 15 minutes), 190 grams more of wood flour were added during the course of about one hour. .Heating at 116-120 C. and stirring were continued for 4 hours, at which time the reaction mixture was viscous and black. It was allowed to cool, diluted with 2 liters of 95% ethanol, heated with stirring until the alcohol refluxed, filtered with suction, and the cellulosic residue was washed well with hot alcohol. The

alcohol and 200 grams of phenol were removed from-the filtrate by heating in a hot water bath in vacuo (2.5 mm. to take off the phenol), The

distillate had collected. The flask was allowed to cool, the water layer (about 1 liter) was de-- canted from the tarry product, about 500cc. of

distilled water was added and steam distillation was continued until test samples of the distillate were free from .phenol (FeCls test). The water which had collected in the flask was decanted and the residual product of crude phenol lignln was allowed to cool. It was a fused, hard, brittle, black mass and weighed 560 grams. It probably did not contain more than 5% of its weight of water.

.The amine resin was made as follows from the crude phenol lignin-described above:

The 560 grams of crude phenol lignin prepared as described above was dissolved in 1,900 cc. of ethanol. The solution was cooled to 8 C. and an aqueous solution of 3,8 mols of dimethylaminomethanolwcs added with mechanical stirring at 8 C. during the course of 15 minutes. The dimethylaminomethanol solution was made by bubbling 171 grams of dimethylamlne into 308 grams of aqueous 37% formaldehyde solution while the temperature was kept 'below 30 C. After the addition of dimethylaminomethanol was completed the ice bath was removed and the solution was warmed to 36 C., at which temperature a mild exothermic reaction set in. Heatin amas was discontinued. The reaction temperature stayed at 36-88. C. for 1.25 hours and then started 7 to drop- The reaction was next heated in a water bath at 85-70 C. for 3 hours. The alcohol solution was allowed to cool and then added slowly to 12.5 liters oi eiilciently stirred distilled water. The resin was precipitated as a finely divided light brown, amorphous solid. It was filtered; washed well with water anddriedflrst in the air' and then in a vacuum desiccator. The dry product was light brown in color and weighed 459 grams. It was soluble in acetone, ethanol, dioxan, chloroform, hot ethyl acetate, 1.5%

aqueous acetic acid, and 5% aqueous sodium hy- I droxide solution.

EXAIPLI C.-Phen0l formaldehyde dimethylamine resin To a solution of 564 grams (6 mols) of phenol in 680 grams (8.4 mols) of aqueous 37% formaldehyde was added, with stirring and cooling at such a rate that the temperature remainedv below 10 C., an aqueous solution of 3 mols of dimethylaminomethanol madeby bubbling 135 grams (3 mols) of dimethylamine'into 243 grams (3 mols) of cold aqueous 37% formaldehyde. The addition of this solution to the phenol solution required about an hour.. The cooling bath was then removed and the temperature of the reaction mixture was allowed to rise spontaneously to 40 C., where it was held by means of a cooling bath until the exothermic reaction was over. The reaction mixture was then heated in a boiling water bath until the resinous mass which was formed was too thick to stir mechanically. It was transferred, while hot, to a large nickel plate, cooled,

and the brittle resin was ground in a cold mor- After drying,'the weight of light yellow, granular, resin was 900 grams. Analysis showed that the product contained 4.94% nitrogen. It was soluble in dilute (1.5%) acetic acid to the extent of at'least 1 gram of resin in 99 grams of acid solution, in 5% sodium hydroxide solution, and in benzyl alcohol and pyridine. It was insoluble in aromatic hydrocarbons. A film flowed from the acetic acid was, after being baked at 100" C. for 15 hours, clear, colorless, hard, and insoluble in dilute acids.- The resin was also soluble to the extent of at least 1% in 1.5% aqueous solutions ofathe following acids: formic, glycollic, lactic, tartaric, phosphoric, and maleic. It was soluble in 0.6% aqueous hydrochloric acid to the extent of 4.5 grams in 95.5 grams of the acid solution. Mineral acids in concentrations of 1.5% or more appear to catalyze hardening of the resin. Consequently they do not dissolve in it. The resin was insoluble in 1.5% aqueous sulfuric acid, n-caprylic acid, and hydrochloric acid.

Exmu: D.-Phen0l formaldehyde dimethylamine resin The above procedure was repeated except that the ratios of reactants were phenol, I moi; formaldehyde 1.4 mols; dimetylaminomethanol, 1 mol.

The resulting resin was a yellow amorphous powder. It was insoluble in all of the common organic solvents except methyl Cellosolve. It was soluble in the theoretical amount of 1.5% aqueous acetic acid and was also soluble in 5% sodium hydroxide solution. A suspension of this resin in ice cold water was dissolved when the water was saturated with carbon dioxide. A film flowed from a dilute (1.5%) acetic acid solution of this resin remained .clear and was soluble in dilute acetic acid after prolonged baking at 100 C.

EXAMPLE E.Phenol-aniline-ammania-formaldehyde resin up to 60 C. The temperature soon dropped to 40 C. The ice bath was removed and 49 grams (0.6 mol) of 37% aqueous formaldehyde were added. The temperature rose immediately to 50 C. After theexothermic reaction had subsided, the mixture was heated in a water bath at 70-90 C. for 2 hours, at the end of which time a thick resin had formed. The resin was purified by the method outlined under Example C above. It was a light yellow, amorphous powder and weighed 135 grams. It was soluble in acetone, ethyl acetate, dioxan, chloroform, 5%. aqueous sodium hydroxide solution, and aqueous acetic acid.

EXAMPLE F. Phenol-formaldehyde-cyclohe:ryl-

amine resin and it was then heated gradually on a water bath up to 90 C; and was held there for 3.5 hours. The resin which formed was purified by the method outlined under Example C. a light yellow, granular solid and weighed 143 grams. It was soluble in acetic acid, ethyl acetate, dioxan, pyridine, and 90% toluene-- 10% ethanol mixture.

EXAMPLE G.-Phenol-formaldehyde-ammonia resin To a solution of 94 grams (1 mol) of phenol in 140 grams of water, there was added 61 grams (1 mol) of 28% aqueous ammonia. The solution was stirred and cooled in an ice bath while 162 grams (2 mols) of 37% aqueous formaldehyde were added. During this time a solid formed. The mixture was next gradually brought to the temperature of a boiling water bath and held there for 1.5 hours during which time a fused mass of resin formed. The resin was purified by the method outlined under Example C above. It weighed 107 grams, contained 5.07% nitrogen, was soluble in acetone and dioxan, but was not completely soluble in acetic acid of concentrations lower than It was also soluble in 5% aqueous sodium hydroxide solution.

There are, of course, numerous other amine phenol formaldehyde resins which are prepared in much-the same manner as described in these specific examples which may be used with good results in improving the dyeing qualities of cellulosic structures, as for example resins prepared from symmetrical xylenol, formaldehyde and methylamine; phenol, lignin, formaldehyde and methylamine; phenol, formaldehyde and cyclo- It was hexanolamine; p-toluene sulfonamide, phenol, formaldehyde and methylamine; diphenylol cyclohexanone, formaldehyde and dimethylaminomethanol; diphenylguanidine and formaldehyde; phenol, formaldehyde and dimethylamine; m cresol, formaldehyde and di-methylamine; xylenol, formaldehyde and,dimethylaminomethanol; phenol, formaldehyde, ammonia and diethanolamine, etc.

'The resins described above may be incorporated in the cellulosic structure in any suitable manner, as for instance by dissolving or dispersing the resin in the cellulosic spinning solutions or by dissolvingor dispersing the resin in a suitable solvent or dispersing agent, impregnating the principles of this invention, it being understood of course that the invention is not limited to these precise examples, which are merely illustrative of the invention.

EXAMPLE I The resin prepared according to Example A from phenol formaldehyde, ammonia and dimethylamine is dissolved in a cellulose acetate spinning solution to the extent of 10%, based on the cellulose acetate present. The cellulose acetate solution prior to the addition of the resin comprises 15% cellulose acetate in a solvent composed of 97% acetone and 3% water. The spinning solution containingthe resin dissolved and uniformly incorporated thereinis spun electrically, for example, in the manner set forth in the United States'patent to Formhals No. 1,975,-

504, into a cellulose acetate thread. A skein of this thread or yarn,'when dyed in the manner described'immediately below is uniformly colored to substantially the same shade as wool dyed in a like bath.

Milling Red R Conc. (color index 430) (see 1932 Yearbook of the American Association of Textile Chemists and Colorists) is dissolved in water to form a dye solution containing 0.2% dye. Twenty-five ccs. of this dye solution, and 0.5 gram of acetic acid are dissolved in 175 ccs. of water. The solution is heated to 40 C. and a 5-gram sample of the yarn introduced, where- 'upon the solution is heated to boiling and boiled for hour, and then 0.5 cc. of 10% acetic acid is added to the dye bath and the boiling con tinued for another V hour. At the end of that time the sample is removed from the bath, rinsed with water and dried.

EXAMPLE II A resin prepared according to Example B from phenol, lignin, formaldehyde and dimethylamine EXAMPLE III A resin prepared according to Example ,0 from. phenol, formaldehyde and dimethylamine is dissolved in a aqueous caustic solution to the extentof 3% resin in the final solution. A piece of cellulose acetate fabric is immersed in this solution which is heated to 50 C., and altemperature. This fabric, when dyed with Brilliant Milling Green B Conc. as in the preceding example is as-deeply colored as a standard sample of wool dyed with the same dye in the same manner.

ExmPLI: IV

A resin prepared according to Example D from phenol, formaldehyde and dimethylaminometh anol is dissolved in 2% aqueous caustic to form a solution containing 1% of the resin. After heating to 80 C., cellulose acetate. staple fibers are immersed in the solution for 5 minutes, whereupon the fibers are removed from thebath, the excess solution drained therefrom and the fibers then placed in a 5% acetic acid bath at 25 C. for 5 minutes. Upon removal of the fibers from the bath, they are rinsed in water and dried at 80 C. When dyed with Brilliant Milling Green B Conc. according to the method described under Example I, it is observed that the fibers take the acid dye to substantially the same extent as does wool.

EXAMPLE V The resin prepared in the manner described in Example A from phenol, formaldehyde, ammonia and dimethylamine is dissolved in 4% acetic acid to form a solution containing 2% resin and this solution heated to 50 C. A skein of cellulose acetate yarn is soaked in this solution for 5 minutes, then removed, the excess solution drained therefrom and the yarn placed in a 5% ammonium hydroxide water solution atroom temperature for 5 minutes, removed, rinsed and dried at room. temperature. The yarn so treated is tested in the same manner as described in any of the preceding examples and is found to have taken the acid dye exceedingly well.

While the preceding examples have been directed more specifically to processes that would show a decided improved affinity of cellulose acetate for acid dyes, it should be noted that in all these cases the material exhibited substantial improvement in affinity for direct dyes as well. On the other hand, if it is desired primarily to improve the aillnity of cellulose acetate material to direct dyes, I prefer to use'certain other resins such as those set forth in the two examples that follow. Likewise, while these two examples are given to illustrate the improvement in cellulose acetate structures for direct dyes, it should also be understood thatin these cases there is a decided improvement in the ailinity of cellulose acetate structures for acid dyes. I

Exmu VI The resin prepared in accordance with Example E from phenol, formaldehyde, ammonia and aniline is added to a cellulose acetate spinning solution comprising 15% cellulose acetate dissolved in a solvent made up of 97% acetone and 3% water to the extent that the solution contains 15% of the resin based on the cellulose acetate present. After thoroughly incorporating the resin in the cellulose acetate solution, the

solutlon'is dry spun in the usual manner and the yarn so produced is tested with a direct dye in the manner described below.

The yarn to be dyed is soaked in an aqueous bath containing 0.5% sodium oleate soap and 0.5% sodium carbonateheated to from 7080 C. for 15 minutes. The yarn is removed and rinsed with water and permitted to drain for a few minutes, after which it is immersed, in a dye bath. The dye bath is made up by dissolving a direct color such as Pontamine Scarlet B (color acetic acid are again added. The boiling is'continued another 15' minutes, the yarn sample removed, rinsed and dried.

The sample of yarn is found to be colored as deeply as wool which is ,clyed in a like manner and in a like dye bath.

EXAMPLE VII A resin prepared according to the procedure given in Example F from phenol, formaldehyde,

dimethylol cyclohexanolamine is dissolved in a 4% acetic acid solution to the extent of 2%.

The solution is heated to 50 C., a sample of normal cellulose acetate yarn immersed therein for 5 minutes, then removed, drained and next placed ,in a 5% ammonium hydroxide water bath at room temperature for 5 minutes. At the end of this time the sample is removed, rinsed with water and dried. The dried yarn-is scoured and ExA r-eu: VIII The resin prepared according to Example C from phenol, formaldehyde and dimethylaminomethanol is added to a viscose solution containing 7% cellulose and 6% NaOH to the extent of 10% resin, based on the celliilose in the viscose solution. viscose is stirred until the resin is dissolved, which" takes about 30 minutes, then evacuated for several hours and spun into the usual sulfuric acid-sodium sulfate spinning bath.

The yarn is collected'on a bobbin or other suitable device and when a cake of the desired size is formed, the bobbin or the like containing the yarn is removed from the spinning machine, washed acid free with water, desulfured (with sodium sulfide solution) and bleached, preferably with hydrogen peroxide. Following bleaching, the yarn is again washed with soft water and dried at 60C. or at any other suitable temperature. The yarn so produced is dyed in a bath in accordance with the procedure set forth under Example I, using for instance Milling Red 8Com. and is found to acquire a verygood depth of color, being substantially equal to a comparable 2,1es,ssa

about 207 depending on the effectiveness of the 1 thermore, since these resins are of high molecu-- The dyes which have been disclosed hereinbefore are merely illustrative of the class of dyes, either acid or direct, and any other dyes generally classified as acid or direct dyes may be substituted therefor. v

It is apparent that this invention considerably widens the range of dyestuffs available for use in cellulose acetate and /or regenerated cellulose threads and fibers. It enables the dyer to use new classes of dyes which can be easily applied, which are relatively cheap and which will produce uniform colors fast to light, washing and other factors tending to aifect the color. Furlar weight, they are slow to diffuse from the fiber and since they are generally of film forming materials, they do not tend to weaken the fiber to the extent the fibers would be. weakened by incorporating therein low molecular weight substances such as monomers. Also, these materials have a further advantage for this use in that they are definitely not volatile and water soluble and therefore resist removal by heat and washing. The invention is particularly useful for improving the dyeing properties of cellulose acetate yarn which has been spun electrically as, for instance, by the method disclosed in United States 7 Patent No. 1,975,504;

By means of this invention regenerated cellulose fibers may be mixed with wool and dyed satisfactorily with acid dyes. Also, regenerated cellulose may be mixed with cellulose acetate yai-n and dyed with either acid or direct dyes. Furthermore, fabrics made from 100% cellulose acetate are simply and inexpensively dyed. As the result of-this invention direct dyes can be used with cellulose acetate fabrics for producing print goods and also with cellulose acetate-cotton mixed goods either for print work where a dischargeable dye is very desirable or where the goods are dyed in a dye bath. It is also possible by means of this invention to mix cellulose acetate materials with wool and secure satisfactory dye results with either acid or direct colors.

While this invention has been described in connection with textile threads, fabrics, etc., it is also useful in connection with other types bf structures. For instance film, sheeting, bands, caps, ribbons, horsehair, straw or the like of cellulosic material may be readily dyed with good results.

Parts and proportions of materials as set forth in the specification and claims refer to parts and proportions by weight unless otherwise specified.

Since it is obvious that many changes and.

modifications canbe made in the above-described processes and products without departing from the nature and spirit of theinvention, it is to be understood that the invention is not to be limited except as set forth in the appended claims.

I claim: a 1

1. The'process which comprises dyeing a cellulosic structure containing a'phenol-aldehydeamine resin with a dyestuif taken from the group consisting of acid and direct dyestuffs.

2. 'lhe process which comprises dyeing a cellu iosic thread composed of artificial fibers and containing a phenol-aldehyde-amine resin with a dyestuif taken from the group consisting of acid and direct dyestuffs.

3. The process which ganic cellulose derivative structure containing a phenol-aldehyde-amine resin with a. dyeduf! taken from the group consisting of acid and direct dyestuffs.

comprisesdyeing'anor- 4. The process which comprises dyeing a celluiosic structure containing a phenol-aldehydeamine resin with an acid dyestuif.

5. The process which comprises dyeing an organic cellulose derivative structure containing a phenol-sldel yde-amine resin-with an acid dyestufi.

6. The process which comprises dyeing an or ganic cellulose derivative structure containing a phenol-aldehyde-amine resin with. a direct dyestufi.

7. The process which comprises dyeing an organic cellulose derivative structure containing phenol-formaldehyde-dimethylamine-ammonia resin with a dyestui'f taken from the group consisting of acid and direct dyestufls.

8. The process which comprises dyeing an organic cellulose derivative structure containing phenol-formaldehyde-dhnethylamine resin with a dyestuil taken from the group consisting of acid and direct dyestuifs.

9. The process which comprises dyeing an organic cellulose derivative structure containing m-cresol-formsJdehyde-dimethylamine resin with a dyestuif taken from the group consisting of acid and direct dyestuffs.

10. As a new article of manufacture, a cellulosic thread comprised of artificial fibers containing a phenol-aldehyde-amine resin and a dyestuif taken from the group consisting of acid and direct dyestuffs.

11. As a new article of manufacture, an organic cellulose derivative structure containing a phenol-aldehyde-amine resin and a dyestufi takan organic cellulose derivative structureoontain ing phmol-formaldehyde-dimethylmnine-ammoniaresinandadyestufftakmfromthe groupof acid and direct dyestuffs.

16. A new article of manufacture comprising an organic cellulose derivative structure containing a m-cresol-formaldehyde-dimethylamine resin andadyestuiftaken fromthe group of acid and direct dyestufls. V

"wmrmm winner: '1'.

I i CERTIFICATE OF CORRECTION; I Patent No 2,168,555. August 8,1959.

, a HINFIELD WALTER HECKER'I'. p It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1; sec- 0nd column,' 1ine 21, for "apaprent" read apparent; page 2, second column,

line 66, for "dimetylaminomethanoi' read dime'thylaminomethanol; pagej, sec

0nd column, line 17, for "fabric" read fabric; page 5, first column, line 6, for "90%" read 95%; and that the said Letters Patent should be read with this correction therein that the same may conform to the record ofthe case in the Patent Office.

Signed and sealed this 26th day of. September, A. D. 1959.

Henry Van Arsdale (Seal) V Acting Commissioner of Patents. 

